> For the complete documentation index, see [llms.txt](https://whitepaper.winnfthero.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://whitepaper.winnfthero.io/4.-gameplay/4.4-allstar/4.4.2-upgrade.md).

# 4.4.2 Upgrade

To start, a player needs to buy Heroes from the Hero Store below. Each Hero has only 1 star by default. A 2-star Hero can be automatically synthesized from 3 identical 1-star Heroes, and so on. A Hero can have a maximum of 3 stars.